Centrifugal switch



Jan. 28, 1930. M. BONNAT CENTRIFUGAL SWITCH Filed April 1. 1927 ZWMJW;

flela jonwei' Patented Jan. 28, 1930 UNITED STATES MAX BONNAT, OF LYON,FRANCE CENTRIFUGAL SWITCH Application filed April 1, 1927, Serial No.180,290, and in France September 18, 1926.

This invention relates to an improved switch of the type in which arotating body is formed with a plurality of passages, each containing aball or roller. The rotation of ithe aforesaid body will tend to keepthese balls out of circuit-closing position in their passages, due tothe centrifugal force exerted on them at such time; but when therotating body slows down to a suflicient extent, then one or more of theballs, according to the position of their carrier body, will travelinwardly far enough to bridge contact between two spaced conductingmembers, and an electric circuit will be closed wherein an audible orother signal is included.

The present invention resides primarily in the construction of theaforementioned rotating body; its object being to simplify and improvethat element and, in particular, to cheapen its cost of manufacture,without in any way decreasing its efficiency. According to theinvention, the rotating body takes the form of a cage which consistssolely of two metal parts or members riveted together, one memberproviding the ball passages, which are merely stamped-out channels,while the other member is a simple, flat plate; the firstnamed orchannel member being insulated by a rubber or other non-conductingwasher from its carrier spindle. Due to this construction, the use of asolid or other block of insulating material, in which the ball channelshave to be formed individually and with considerable care, and which isalways more or less fragile, is entirely avoided, the only insulationrequired being the rubber washer which is directly interposed betweenthe channel member and the spindle. Furthermore, the channels themselvesneed not be specially curved so as to maintain the balls actually attheir outer ends during normal rotation of the cage; but, on thecontrary, they serve merely to retard the inward movement of the ballsand may, therefore, be arranged radially and along straight lines,

though, if preferred, they can be formed with pockets at their outerends which may extend laterally in either or both directions.

The present switch mechanism is specially applicable to yarn winding orunwinding machinery for the purpose of automatically signalling thebreaking of the thread or yarn, and in which it provides a support forthe bobbin, spool or other element whereon the bobbin is being wound, orfrom which it is being unwound; but it is to be understood 11131] otheruses of the application are possi- In the accompanying drawing:

Figure l is a part-sectional side elevation of the improved switch andits mounting;

Fig. 2 is a vertical section through the channel member of the ballcage;

Figs. 3 and 4: are views similar to Fig. 2, but showing pocketedchannels. 5

As represented in the drawing, the switch comprises two main members,the ball cage and its carrier spindle. The spindle itself is composed oftwo metallic members 1 and 2 which jointly support the ball cage attheir mutually-adjacent inner ends. This cage consists simply of twometal members 3 and 4, of which the member 3 is merely a fiat circularplate or disk, while the member 4 is provided with a set of channels 5of semicircular section which are stamped or pressed out from the metalof the otherwise flat plate. These two members are arranged face to faceand fastened directly together by rivets 7, and the channel member orplate t is preferably formed with a marginal flange or rim 8 whichextends across the edge of plate 3 and fits against the same.

In their simplest form, shown in Figs. 1 and 2, the channels 5 aredisposed radially of plate at along straight or substantialy straightlines and at equiangular distances apart; and there is preferably aneven number of them (four, in the present instance), so that the effectis the ear e as if half the number of 90 diametric channels wereemployed. If desired, however, each channel may be provided at its outerend with a lateral pocket 6 which may be single (Fig. 3) or double (Fig.4:) according as rotation of the switch is to take place in onedirection only or in either direction alternatively, as indicated by thearrows.

The cage is designed to house a set of balls or rollers 9, one for eachchannel, made of brass or other suitable metal, which are utilized toclose an electric circuit wherein the warning signal (not shown) isincluded, by bringing the gap between the inner ends of the spindlemembers 1 and 2, which ends are preferably reduced or pointed;

Such circuit, as will be understood, must be kept open under normalrunning conditions; and to effect this, a washer 10 is interposedbetween the hub of the channel plate A and the spindle member 1, so thatcurrentwill pass from one spindle member to the other when, and onlywhen, one of the balls contacts with the reduced ends or terminals ofboth members. It is to be observed that the several channels meet attheir inner ends at the center of plate 4, at which point the spindlemember passes through said plate and projects for a slight distance intothe cage, and that the other spindle member 2 in like manner passesthrough the center of plate 3 and slightly into the cage.

As has already been stated, the spindle 1-2 of the switch device isdesigned to carry a I spool or bobbin whereon the thread is to be woundor from which it is to be unwound; such operations entailing, in oneinstance, the application of a positive driving force to the spindle torotate it and, hence, the spool, and in the other instance, the rotationof the spool by the unwinding thread and, consequently, the rotation ofthe spindle by the spool. Any suitable mounting for the device may, ofcourse, be provided, as for instance that represented in Fig. 1, wherein11 and 12 designate metal supports-to which the two wires 13 and 14 areconnected having bearing openings to receive the outer ends of thespindle members- To retain the spool in place upon the spindle, themember 1 thereof may carry one or more spring clips 15 whichfrictionally engage the bore of the spool.

In operation, the rotation of the spindle and cage incidental to thewinding or unwinding of the thread sets up a centrifugal force which isexerted upon the balls 9 in opposition to their normal inward orgravital movement in their respective channels toward the center of thecage or, in other words, toward the confronting inner ends of thespindle members. As the speed of rotation increases, the balls tend tomove outward and, if a high enough speed is attained, to assume andmaintain a position at the outer ends of the channels; but upon adecrease in speed,

the retarding action created by centrifugal force likewise decreases andthe centripetal or gravital force will tend to prevail, with the resultthat the balls move inwardly toward circuit-closing position andultimately reach that position when the speed falls low enough. Hence,at one extreme of speed the balls will be kept in the outer ends of thechannels, while at the other extreme the'signal circuit will be closed.Between these two extremes, the balls will travel outwardly or inwardlyin their channels in one direction or the other, according as the speedincreases or decreases.

)Vhen the pocketed channels are utilized, the operation is substantiallythe same as before, excepting that the balls will remain in the pocketsduring much lower speeds than would be possible with straightcha-nnels.In the case of the single pockets, shown in Fig. 3, which extend on oneside only of the channels, the cage isintended to be rotated in onedirection only (counterclockwise, in the arrangement illustrated) butwhere double pockets are employed, which extend on both sides of thechannels (Fig.4), the cage can operate for either counterclockwise orclockwise rotation.

I claim as my invention 1. A centrifugal switch, comprising a rotarycurrent-collecting spindle. embodying two structurally-separate sectionshaving a gap between their mutually-adjacent inner ends; a cagesupported jointly by the two spindle sections and. consisting of twothin, metal disks fastened together face to face and mounted one on onesection and the other on the other section, a single one of said diskshaving a series of radial channels stamped out from it which meet attheir inner ends at said gap so as to enclose the latter within thecage; a conducting roller disposed in each channel to travel in oppositedirections therein according to speed variations'and to bridge the gapwhen the speed falls below a certain value; and an insulating washerinterposed between the hub of the channeled disk and the correspondingspindlesectionto prevent the passage of current between that section andthe other segtion until the gap is bridged.

2. A centrifugal switch, comprising a rotary current-collecting spindleembodying two structurally-separate sections having a gap between theirmutually-adjacent inner ends; a cage supported jointly by the twospindle sections and consisting of two thin, metal disks fastenedtogether face to face and mounted one on one section and the other onthe other section, a single one of said disks having a series of radialchannels stamped out from it which meet at their inner ends at said gapso as to enclose the latter within the cage, each channel having alaterallyextendingpocket at its outer end; a conducting roller disposedin each channel to travel in opposite directions therein according tospeed variations so as to bridge the gap when the speed falls below acertain value and to enter the respective pocket when it becomessufliciently high; and means for insulating the channeled disk from thecorresponding spindle section to prevent the passage of current betweenthat section and the other section until the gap is bridged.

3. A centrifugal switch, according to claim 2, in which theroller-receiving pockets project laterally from both sides of thechannels.

In testimony whereof I afiix my signature,

MAX BONNAT.

